This invention relates to optical fiber or fiberguide connectors.
Fiber-optic communication channels have great promise as the "wire and cable" of tomorrow. They have larger signal carrying capacity, are lighter in weight, smaller in size and potentially lower in cost than their electrically conductive counterparts. In addition, they are immune to electromagnetic and radio frequency interference and offer advantages in eliminating cross-talk and in assuring privacy.
Recent improvements in fiber-optic transmission lines, both in performance and in mechanical strength, are impressive and promise widespread application in the very near future. One of the persistent problem areas, however, in the practical application of fiber optics for communications has been that of the optical fiber connector.
The problem of connecting fibers can be simply stated. Adjacent fiber ends must be flat, perpendicular, and polished as well as aligned axially and transversely. The difficulty arises when dimensional tolerances are considered. In order to keep optical loss negligible, i.e., about 0.1 dB, the transverse alignment error must be less than 1/20 the fiber core diameter and the axial separation less than 1/2 the core diameter. Practical multi-mode fiber core diameters are likely to be 50 to 250 .mu.m (0.002 inch to 0.010 inch), and therefore positional errors of the fiber core of even 0.0001 inch would result in measurable loss. Another requirement not imposed on wire connectors is that of cleanliness. The making or breaking of the connection must not generate debris that could obstruct the light path or alter the alignment of the fibers.
The necessary alignment could be accomplished by making an adjustable connector, but this procedure would be cumbersome and the apparatus costly. Many designs involving numerous complex parts machined to close tolerances have been shown to operate satisfactorily, particularly with the larger fibers or fiber bundles. See, for example, T. Bowen, "Fiber Optics as an Interconnecting Medium," Electronic Packaging and Production, pp. 17-32 (April 1976). Whether or not such designs, if standardized and made in large quantities, would be reasonable in cost is yet to be demonstrated.
It is therefore an object of my invention to provide a simple, precise, low cost optical fiber connector.
It is another object of my invention to alleviate the need for expensive machining of connector parts to critically tight tolerances, it being possible to assemble my connector largely from inexpensive, off-the-shelf, precision components.